diff --git a/litellm/llms/openai_like/chat/handler.py b/litellm/llms/openai_like/chat/handler.py
index 821fc9b7f15..25b7fc2e98c 100644
--- a/litellm/llms/openai_like/chat/handler.py
+++ b/litellm/llms/openai_like/chat/handler.py
@@ -272,7 +272,11 @@ class OpenAILikeChatHandler(OpenAILikeBase):
                 )
 
         data = {
-            "model": model,
+            # watsonx: Deployment models do not support 'model_id' in their payload
+            # https://github.com/BerriAI/litellm/issues/11837
+            "model": None
+            if custom_llm_provider == "watsonx" and model.startswith("deployment/")
+            else model,
             "messages": messages,
             **optional_params,
             **extra_body,
diff --git a/tests/llm_translation/test_watsonx.py b/tests/llm_translation/test_watsonx.py
index e0c125a9017..e399c6de7a9 100644
--- a/tests/llm_translation/test_watsonx.py
+++ b/tests/llm_translation/test_watsonx.py
@@ -207,6 +207,7 @@ def test_watsonx_deployment_space_id(monkeypatch, watsonx_chat_completion_call,
     assert mock_post.call_count == 1
     json_data = json.loads(mock_post.call_args.kwargs["data"])
     assert my_fake_space_id not in json_data
+    assert json_data.get("model") is None
 
 
 def test_watsonx_deployment_space_id_embedding(monkeypatch, watsonx_embedding_call):
@@ -218,3 +219,4 @@ def test_watsonx_deployment_space_id_embedding(monkeypatch, watsonx_embedding_ca
     assert mock_post.call_count == 1
     json_data = json.loads(mock_post.call_args.kwargs["data"])
     assert my_fake_space_id not in json_data
+    assert json_data.get("model") is None